In recent years, a variety of Internet services such as Web browsing and IP telephone services under a wireless LAN environment at home or at an office (hereunder, referred to as “in home”) by using mobile telephones configured to connect to a mobile telephone network (including so-called “smartphone”) have become available. These mobile telephones are provided with a wireless LAN communication unit (Wi-Fi (registered trademark) function that conforms to the IEEE 802.11 standards) and thus configured to connect to the Internet under the wireless LAN environment.
Meanwhile, Japanese Utility Model No. 3116750 (hereinafter, referred to as PTL 1) and Japanese Patent Application Laid-Open No. 2003-101632 (hereinafter, referred to as PTL 2), for example, disclose a technique for connecting by radio a mobile telephone with another telephone such as a cordless telephone handset (hereafter referred to as “cordless handset”) used at home and then transferring various kinds of data (e.g., telephone directory data, wallpaper data, and ringtone data) held in the mobile telephone to the other telephone. Note that, the ringtone data may be sound source data used in a cordless handset, such as a holding tone or a guidance message of an answering machine.
PTL 1 discloses a telephone capable of coupling an external storage apparatus (for example, a mobile telephone) to the telephone, reading an audio file from the external storage apparatus, and freely changing a ringtone.
PTL 2 discloses a telephone directory data transfer system that connects a mobile telephone and an extension telephone (or a general subscriber telephone) and allows telephone directory data to be transferred between these telephones.